         (add-module-lesson-group moduleCode
                                  (:lessonType modInfo)
                                  (:lessonGroup modInfo)
-                                 bgColorCssClass)))
+                                 bgColorCssClass
+                                 true)))
 
     ; Update url hash
     (set-document-location-hash-based-on-modules-order)))

                                   (:lessonType moduleInfo)
                                   (:lessonGroup moduleInfo)
                                   bgColorCssClass
                                   ModulesMap))

        ; Update URL hash with newly added module

      (doseq [siblingTdElem (take (- slotsOcc 1) (.nextAll tdHTMLElem))]
        (.remove siblingTdElem))

      ; Returns a `ModulesSelectedLessonInfo` object augmented with the
      ; `:divElem`, `:moduleCode`, `:lessonType`, and `:lessonGroup` keys
      {:day day, :rowNum rowNum, :startTime startTime, :endTime endTime,
       :moduleCode moduleCode, :lessonType lessonType, :lessonGroup lessonLabel,
       :divElem $divElem})))

; Forward declaration
(declare add-module-lesson-group)

(defn- lesson-draggable-start-evt-handler-maker
  "Returns a function that can be used as the `start` event handler for a
